Internal-combustion engine.



0. OHLSSUN.

INTERNAL GQMBUSTION ENGINE.

APPLICATION FILED MAY 22, 1907.

Patented Mar. l0, WM.

Z HEETE-BHEBT l,

0. DHLSSGN.

Patented Mali M), 19M.

2 SHEETS-SHEET 2.

Ell

@LOF OHLSSO, GF SODERTELJE, SWEDEN.

INTERNAL-CCMBUSTON ENGINE.

maaien.

Specicaton of ILetters Patent.

Patented Maiz lill, lgld,

Application tiled May 22, toi Serial No. 375,069.

To all whom it may concern Be it known that l, @Lor @HL-esca', a subject of the King of Sweden, and resident of Sodertelje, Sweden, have invented certain Improvements in internal-Combustion Engines, of which the following is a specication.

ln internal combustion engines, such as have been heretofore employed, the charge, consisting of a suitable quantity of vaporized fuel such as petroleum, for example, or a combustible mixture of such vaporized fuel with air has ordinarily been directly introduced into the working cylinder in such a manner that a very sudden and high pressure, similar to that of a heavy explosion results when the charge is ignited, which pressure operates as a violent blow upon the piston, while the same is at the termination of its return stroke and before the coniniencement of its forward stroke. Under such circumstances, it is very diflicult to effect the regulation desirable to meet varying requirements of power and irregular ruiming of the engine results, and as the inertia of the fly wheel cannot be overcome with sufficient 'apidity a great strain is imposed upon the parts, nor can the high temperatures which result from the excessive pressure developed at ignition of the charge be fully utilized and consequently .a great part of the heat of the fuel is not converted into mechanical work but is lost.

ein important object of the present invention is to provide means whereby these disadvantages are avoided. rl`his is attained by dividing the combustion period into two or more periods, the first one taking place in a special primary chamber and the other one in a secondary cnamber opened inward to the working or piston chamber and communicating with the primary chamber, the communication between the primary chamber and secondary chamber being valve controlled. The combustible gas or the fueland a quantity of air are introduced in the primary chamber and are mingled in the same and preliminarily ignited, a preliminary high pressure being thus effected in the same during a combustion process which is 'only partial owing to the surplus of fuel in proortion to the air. The igniting operation is effected in the primary chamber when the piston is at or near the outer reversing point, the ignition being dependent upon the cempression or the pressure of the air previously introduced in the working chamber which compression is effected by the piston. The valve controlling the communication between`the primary chamber and secondary chamber is now opened at the pressure in the primary chamber and the ignited charge enters thesecondary chamber. When meeting the compressed air in the secondary chamber, lthe combustion is completed. The said completed combustion acts, like the ignition in the primary chamber, as an eX- plosion but this explosion/.is however of a comparatively mild character owing to the fact that the compressed air has a comparatively greater velume with relation 'to the charge supplied through the valve for which volume there is room in the secondary chamber. rlhe pressure now increases to or, more correctly, is fully maintained at the degree which corresponds to the complete combustion so that' the heat of the fuel is fully utilized. ln addition to the increased edect already intimated advantage is attained by the said construction, that the explosion in the secondary chamber is not effected until the piston has arrived at or near the reversing point on its upward or return stroke or, if this be necessary, until after the piston shall have commenced its downward or advanced stroke, and that if the volume of combustible `fuel supplied tothe engine is varied to meet the varying requirements et developed power, this will not interfere with the functions of ignition and combustion, the complete combustion of the charge being assured irrespective of such variations within the limits of the air supply. Further it may be stated that an engine constructed in accordance with this embodiment of the invention works with great expansion and at a comparatively low pressure and moderately high temperature owing to which facts it is more durable than engines hitherto employed.

rlhe invention consists in certain novel features of the construction, and combinations and arrangements of the several parts of the improved engine, whereby certain important advantages are attained, and the device is rendered simpler, less expensive and otherwise better adapted and more convenient for use, all as will be hereinafter fully set forth.

The nevel features of the invention will he carefully defined in the claims.

l' ln order that my invention may be the companying drawings, whereinof a part Figure 1 is a vertical section 'of an engine constructed in accordance with an embodiment of my invention; Fig. 2 is a section on the line A-B of Fig. 1; Fig. 3 is aV section of the passage leading to the primary chamber and provided with an absorbent reservoir or retainer for the fuel; Fig. ,4 is a section on the line C-'D of Fig. 1; Fig. 5 illustrates the mixing device, which is located in the bottom part of the primary chamber and mixes the gas and air with. each other; and Figs. 6,. 7 and 8illustrate further embodiments of my invention.

l'As-'herein shown the improved engine has the piston 2 which reciprocates in the cylinder or working hamber 1 and is connected with the crank 4 by means of the connecting rod 3, the same being as usual surrounded by a. casing forming a compression chamber 5 in which vacuum and pressure are alternately produced by the iston. The primary chamber 6 is provi ed at the side of the cylinder. The upper end of the working chamber 1 is provided with a wide channel or secondary chamber 7 forming an extension thereof, and in communication with the primary chamber 6 but separated therefrom by the valve 8.

The valve 8 may be so arranged that it can be opened outward from the primary chamvber 6 as show-n in Figs. 1 and 6 or inward toward the said chamber as shown in Fig. 7, and is acted upon by a spring as shown in Fig. 1 or connected with a lever as shown in Figs. 6 and 7.

In the bottom or lower end of the primary chamber 6 is provided a mixer 9 shown on anenlarged scale in Fig.A 5, andbelow the said mixer the chamber 6 communicates with the upper part ofthe workinglchamber 1 through a pipe or channel 10 which extends into the mixer and has a mouth l0 directed downward. Exterior of the chamber G'the said pipe or channel 10 is provided with a regulatingy valve 11. A channel 12 of greater diameter than the channel 10 leads from the bottom or lower end of the primary chamber 6 and communicates with the bottom or lower end of the working chamber 1 through an opening 11 and with the crank or compression chamber 5 through a branch pipe or channel 15. The channel 12 is separated from the chamber 6 by the valve 13 and the branch pipe or channel 15 is provided with a regulating valve 16, said valve 16 being under control of suitable governor mechanism (not shown). The channel 12 is arranged on a curve directed downwardly and the absorbent fuel retainer or reservoir 17 hereinbefore mentioned extends within the lower part of the same. The said absorbent fuel retainer or reservoir 17 consists l of a highly porous body acting like a strainer and produced by rolling up a ne brass-wire cloth or in any other suitable manner. The absorbent retainer or reservoir 17 communicates with a channel 18 leading from the Afuel tank (not shown) and .provided with a controlling valve 19 as is particularly shown in Fig. 3. A mixer is contained within the primary chamber 6 and consists of a plurality of disks 21 located one above the other and at some distancei'zrom each other. Each disk has two transverse passages 21x provided on the same diameter and the passages of each two adj acent disks are set at angles of 90 with relation to each other, so that the passages-21 are situatedin staggered relation or zig-Zag lines throughout the disk pile. The chamber 6 is also provided with an igniter which may be of any suitable construction, as for instance, it may consist of a tube 20 as shown in Fig. 1. The working chamber l communicates with the atmosphere through an opening 22 and4 the crank or compression chamber 5 communicates through a channel 25 with cavities or spaces 24 in the cylinder wall and cover, such cavities or spaces being provided with inlet openings 23 to the atmosphere.

The piston 2 acts, as usual, both as a working piston, z'. e. is acted upon by the pressure of the expanding combustion gases and transmits the said pressure to the crank, and as a compressing piston for compressing the air in the cylinder l above the piston and in the crank chamber 5 alternately, said piston also creating a vacuum in the chamber last mentioned when moved upward. The pressure eiiected above the piston during the -compression of the air is transmitted to the Chamber 6 through the pipe or channel 10. The air compressed in the chamber 5 is used partly for blowing olf the combustion products .from the cylinder 1 above the piston when the latter is in its lowermost position and partly for causing the fuel to pass through the channel 12 to the mixer 9 in the chamber 6.

The engine works in two strokes and effects a compression at every stroke upward and is subjected to the pressure of combustion at every stroke downward. fis the piston moves upwardly, vacuum is created in the compression or crank chamber 5 as hereinbefore stated, which vacuum is also effective in the channel 12 shut off by the closed valve 13 and by the piston covering the opening 14. Owing to this fact fuel is sucked into the retainer or reservoir 17 and as duringthe i-acuumperiod no air current worth mentioning passes through the reservoir, the fuel remains the same. Consequently after the sucking operation has been effected the reservoir oi' retainer acts substantially'like a moist sponge which can tively small quantity of fuel which is neces-Y sary for every working stroke a very small quantity ofai-r may advantageously be led into the petroleum at the valve 19. This air, however, is not absolutely necessary. For this ur ose a narrow passage 19x is provided) alibve the said valve 19 (Fig. 3)

through which a small quantity of air may pass. As the piston is moved downwardly a pressure is created in the chamber 5 which as has been hereinbeforestated is eifected also in the channel 12. The valve 19 provided in the conduit between the reservoir and the fuel tank, is then closed. \As the piston is moved farther downward the opening 22 is uncovered while the opening lll remains' covered due to the fact that the opening 22 has a greater diameter vertically than the opening 14: and the lower side walls of said openings bein on the same plane or level as is clearly s own in Fig. 1. When the chamber above the piston has been put into communication with the atmosphere, as has been described, the air in the channel 12 moves rapidly toward the chamber 6. This air causes the fuel in the reservoir 17 to pass with it and carries same past the valve 13 of the mechanism 9 which has been heated durin the previous combustion period. lDurin t is operation the valve 13 1n its opene or lifted position closes the mouth 10 so that the charge cannot pass into the channel l0. As the piston is moved farther downward the opening 14 is uncovered. The greater part of the compressed air 1n the chamber 5 passes through the cylinder to the atmosphere, the cylinder being thusv freed from the. products of combustion from the previous stroke and is iilled with fresh air. As the air passes to the chamber 6 it carries the fuel with it from the beginning but owing to the greater weight of such fuel and the obstruction offered by the mixer the fuel is retarded in its movement. This causes the fuel to become divided which results in an effective mixing of the fuel and the air while the currents pass from and toward each other alternately in the spaces of the mixer and the openings, which continues during the movement upward of the fuel and the air, the fuel being at the same time heated and evaporated. This occurs even at tively narrow channel 12 does not ermit the pared with the quantity of air necessary for the full combustion of the supplied fuel. As the piston turns back the pressure in the channel 12 is so reduced that the valve 13 closes. Owing to the fact that the mixer possesses greater heat at its upper part than at its lower part, the charge isA gradually heated as it travels lengthwise of the mixer. This length of travel can be yextended or shortened by making the disks or the spaces thicker or thinnerand thus employ a greater number of disks or by making the openings 21x wider or narrower and so on. The action of the mixer is dependent on the narrow shape of the spaces and on the position of the openings in staggered relation or zig-zag lines, in consequence whereof the air and the fuel are divided into currents which cross and pass each other continuously. As the piston is moved upwardly the air in the piston chamber and the primary chamber which is in communication with the piston chamber through lthe channel 10, is compressed more and more. However, the pressure in the chamber 6 does not increase with the same rapidity as in the piston chamber and the secondary chamber 7 due to the resistance exerted by the ipe 10A which resistance can be increased or decreased by means of the valve 11. Consequently, it is possible to cause the pressure in the chamber 6 to reach its maximum only when the piston has been reversed. The fact is that the pressure in the chamber no doubt can be increased `though the piston has been reversed for though the movement downward ofthe piston causes a reduction of the pressure provided there is nothing causin an additlon to the pressure, the pressure a ove the piston is great enough as long as the piston 1s in the vicinity of the reversing point to cause the air to continue in its movement to the chamber 6 unt-il pressure is the same in both chambers. Owing to this fact it is possible to regulate the pressure in the primary chamber and to fix the osition of the crank at the moment when t e pressure in the chamber has reached its maximum so` that the piston has .alread been reversed and has passed downwar 3 a greater or shorter distance which facts are of great importance for the operation of the engine. The maximum pressure in the chamber 6 effects the ignition of the charge in the same.

However, the said ignition is dependent noteasily controlled partly by means of the.

6 substantially at the end of the compression period, as -the pressure then increases rapidly. The said air forces the gas mixture upward in the chamber 6 and dilutes the same to such a degree that the bottom part of the chamber is filled with the normal mixture while the top part of the chamber is still lled with a mixture in which there is a great surplus of fuel. Consequently an ignition or primary explosion takes place in the chamber 6 as the piston is at or near the upper reversing point. This primary explosion cannot be more violent than permitted by the air forced into the chamber through the pipe 10 and takes place in the bottom part of the chamber only. The gas mixture in the top part of the chamber cannot burn owing to the lack of air but it is heated to a great extent. The valve 8 is opened byv the increased pressure and the mixture is forced from the chamber 6ihto the chamber 7 in which it is brought in contact with the compressed air. Here the second and complete explosion takes place and the fuel of the mixture burns up completely. During the said operation the pressure is not increased much but on the other hand it remains at a substantially constant degree for a longer part of the plston stroke owing lpartly to the fact that the combustion takes place successively according as the fuel and the air have time to come in contact with each other in the same extended channel of the secondary chamber 7; and partly to the expansion of the comparatively great quantity of air in the secondary chamber 7. The fact is that the secondary chamber 7 has such a capacity that the quantity of air held by the same considerably exceeds the quantity necessary for the combustion of the charge. As the piston is near thelower reversing point the combustion gases escape through the opening 22 with a very low pressure and a low temperature. Therefore the pressure originally effected in' the chamber 6 partly bythe piston and partly in the ignition is now consumed.

The engine may be so constructed that the secondary chamber 7 forms a part of the piston chamber proper. The channel l0 may be provided with a valve ll c closing the same in a direction from the chamber 6 (F ig. 7). As the channel 12 extends downward in a curve 'fuel which possibl drops from the reservoir or channel 17 will gather on the bottom of the channel and is carried with the air when forced into the chamber in the succeeding operation.

The construction illustrated in Fig. 7 differs from the construction shown in Fig. l

` in the period between the first and second explosions being not left to itself but made dependent on the motion of the engine. The said period can be lengthened or shortened owing to the velocity of the engine, the fuel quantity, the load of the engine and so on. The pipe l0 is somewhat larger than in Fig. l so ,that the compressed air can enter the bottom partk of the chamber 6 more easily and rapidly or, in other words, so vthat the pressure in the chamber 6 increases with substantially the same'rapidity as in the secondary chamber 7. During the compression period as soon as such a quantity of air has entered the bottom part of the chamber 6 as is necessary to attain a certain inflammability or rapid inammability of the mixture in the same to form the required mixture, the rst explosion takes' place. At the same moment, the pressure in the chamber 6 increases and the valve 8 is shut so that communication with the piston chamber is interrupted. Consequently, the said first explosion may take place at any position of the piston without any retarding action on the movement outwardof the piston. The pressure in the chamber 6 is stored, so to say, owing t0 which fact more time is gained for the heating of the gas in the top part of the chamber until the moment when the piston passes the reversing point, or immediately afterward when the valve 8 is opened mechanically and the charge enters the secondary ,chamber 7 and is completely burnt therein. The valve 8 is operated by any suitable meansto keep it in open position and is held in closed position by a spring or the like during the compression period.

In the form shown in Fig. 8 two relatively parallel primary .chambers are employed. The construction of the same need not be especially explained. The said chambers may act either simultaneously or alternately and in the latter case admitting the charge into the secondary chamber 7 alternately. In this embodiment of the invention two compressing chambers may be used.

' It may here be statedv that careful examinations have 'shown that the gas mixture heated during the preliminary ignition is extremely inflammable in consequence whereof the secondary combustion is very complete.. There is a great advantage in having the temperature in the chamber 6 always the same or substantially the same independently of the work of the engine nosa/isa which is due to the fixed limit of the com bustion operation in the said chamber. Therefore the change of the temperature in the working chamber caused by the combustion in the secondary chamber 7 and the movement of the piston can have no disturbing effect upon the preliminary ignition of the first combustion. IThis assures the engine working in a reliable manner even under the most varying conditions.

W'hen the piston has been moved upwardly a sufficient distance to uncover the channel Q5 the atmospheric air 4entering through the opening 23 passes through the spaces 24 in the cylinder wall and through the channel 25 into the crank chamber in which a partial vacuum has been created during the movement of the piston. In this manner refrigeration of the working cylinder by means of air is effected in the cylin der wall and by means of the air entering the chamber 5 the heat is saved which is otherwise lost by radiation.

The ignition tube 20 hereinbefore referred to isused only at the starting'of the engine or during cold weather when the external air may unduly chill the parts.

As already stated the engine may be so arranged that it opens the valve 8 by means of a cam acting on a lever or the like connected with the valve either outwardly (Fig. 6) or inwardly against the resistance of a spring (Fig. 7).

In addition to the described mode of action characteristic of the engine the simplicity and durability of the engine in com parison with those hitherto used may, be pointed out.

The sound damper, as well as the water cooling device can be dispensed with owing to the low pressure and the moderately high temperature, as also may all extra devices hitherto used for-the coolingand lubrication of the piston. all parts of the engine being subject to a less violent strain.

From the above description it will be seen that the improvedk internal combustion engine constructed in accordance with my invention, is of an extremely simple and comparatively inexpensive nature and is particularly well adapted r use by reason of lits strength and convenience of operation and it will also be obvious from the above ldescription that the device is susceptible of that the dimensions of the cylinder l with relation to the primary chamber v6 and the secondary chamber 7 respectively,- may be varied and also the degree of compression dependent upon the desired degree of eX- pansion.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. An internal combustion engine having a cylinder, a piston movable therein, a primary chamber having unyielding walls, means for admitting a combustible charge to the primary chamber, and means for admitting air to the primary chamber, said piston being adapted for successive operation lirst to supply a combustible charge to the primary chamber and afterward to supply air thereto to increase the pressure therein, a secondary chamber adapted to afford communication from the primary chamber to the cylinder ofthe engine, means Jfor admitting a supply of air to the cylinder, means to close communication between the primary chamber and the secondary chamber during compression of the charge in the primary chamber, and means operable upon the compression stroke of the pisiton for igniting the combustible charge in the primary chamber whereby the same is caused to kbe discharged into .the secondary chamber and mingled with the air therein contained. 9. An internal combustion engine having a cylinder, a piston movable therein, a primary chamber having unyielding walls, means for admitting a combustible charge to the primary chamber` means for admitting air to the primary chamber, said piston being adapted for successive-operation to supply a fuel charge to said primary chamber and afterward to supply air thereto, increasing the pressure therein, a secondary chamber adapted to afford communication between the primary chamber and the cylinder of the engine, means for admitting air to the cylinder, a valve controlling communication between the primary chamber and the secondary chamber and adapted to remain normally in closed position, and means operable upon the compression stroke of the piston for igniting the combustible charge in the primary 'chamber whereby the same is caused to be discharged into the secondary chamber and mingled with the air therein contained.

3. An internal combustion engine having a cylinder, a piston movable therein, a primary chamber, a secondary chamber affording communication from the primary chamber to the cylinder, means for controlling communication from the primary chamber to the secondary chamber, a mixing mem ber extended in the primary chamber, means for supplying a combustible charge to the Lid mixing member, means for directing a supply of air lalong the mixing member for admixture with the combustible charge, and means operable upon the compression stroke of the piston for igniting the charge in the primary Achamber to cause the same to be discharged into the secondary chamber and mingled with the air therein contained.

4. An internal combustion engine having a cylinder, a piston movable therein, a primary chamber, a secondary chamber affording communication from the primary chamber to the cylinder, means for admitting a supply of air to the cylinder, means for controlling communication from the primary chamber to the secondary chamber, means for admitting a combustible charge to the primary chamber, a mixing member in the primary chamber, and means for supplying a currentof air from the cylinder to the mixing member in a direction to force the combustible charge through the mixing member toward the secondary chamber.

5. An internal combustion engine having a cylinder, a piston movable therein, a primary chamber, a secondary chamber affording communication from the primary chamb er to the cylinder, a compression chamber, means for admitting air to the cylinder, a passage affording communication between the primary chamber and the cylinder, a second passage affording communication between the primary chamber and the compression chamber, means for supplying fuel within the said second named passage, said piston being capable of operation first to draw fuel into thesaid'second named passage and afterward to increase the tension of air in the compression chamber whereby the Isame is forced through the second passage into the primary chamber, and means for igniting the charge in the primary chamber.

6. An internal combustion engine having a cylinder, a primary chamber, a secondary chamber affording communication from the primary chambertothe cylinder, a rear compression chamber adapted to contain a supply of air, means for admitting a supply of air thereto, means for'admitting air to the cylinder, a fuel supply passage. affording communication from the rear compression chamber to the primary chamber, means for supplying fuel to said passage, a piston in the cylinder and adapted, when moved in one direction, to lower the air pressure, in the compression chamber whereby fuel is drawn into said passage and when moved in the reverse direct-ion to increase the pressure in said compression chamber, whereby said fuel is forced from said passage into the primary chamber and means for igniting the charge in said primary chamber.

7. An internal combustion engine having a cylinder, a primary chamber, a secondary chamber affording communication from the primary chamber to the cylinder, means for admit-ting a supply of air to the cylinder, a fuel supply passage adapted for communication with the primary chamber, means for supplying fuel to said passage and comprising a fuel supply pipe and a porous fuel reservoir located in such passage and adapted to receive fuel from said supply pipe and means including a piston operable in the cylinder capable of operation rst to draw fuel from said fuel supply pipe into said porous reservoir and afterward to force air through such passage to vaporize the fuel carried by the reservoir and convey the same into the primary chamber, and means for -igniting the charge in the primary chamber.

8. An internal combustion engine having a cylinder, a primary chamber, a secondary chamber affording communication between the primary chamber and the cylinder, means for admitting a supply of air to the cylinder, a passage affording communication between the primary chamber and the cylinder and being arranged on a downwardly directed curve, a compression chamber, a second passage affording communication between the primaryv chamber and the compression chamber, means for supplying fuel to said second named passage and comprising a fuel supply pipe and a porous fuel reservoir located within the curved portion of the passage and adapted to receive fuel from said pipe, a piston movable in the cylinder capable of operation, first to draw fuel from the supply pipe into said reservoir and afterward to force air through the second passage into the primary chamber, and means for igniting the charge in the primary chamber.

9. An internal combustion engine having a cylinder, a primary chamber, a secondary chamber affording communication between the primary chamber and the cylinder, a compression chamber, means for admitting a supply of air tothe cylinder, a passage affording communication between the primary chamber and the cylinder, a valve controlling said passage, a second passage affording communication between the primary chamber and the compression chamber, means for supplying fuel within the second named passage, means including a piston movable in the cylinder and capable of operation, rst to draw fuel into the second named passage and afterward to increase the tension of air in the compression chamber whereby the same is forced through the second passage into the primary chamber, and means or igniting the charge in the primary cham- 10. An internal combustion engine having chamber t0 the cylinder, means for admitting a supply of air to the cylinder, a rear compression chamber, ducts formed in the cylinder Wall and forming an air inlet for the compression chamber, a passage aording communication from the compression chamber to the primary chamber, a piston in the cylinder arranged to increase the tension of the air in the compression chamber Whereby the same is forced through said passage into the primary chamber, and means for igniting the charge in the primary chamber.

l1. An internal combustion engine having a cylinder, a primary chamber, a secondary chamber affording communication from the primary chamber to the cylinder, means for admitting a supply of air to the cylinder, a rear compression chamber, a passage affording communication from the rear compression chamber to the primary chamber, means for supplying fuel to said passage, a piston to lower the air pressure in such chamber,`

said duct being closed during the reverse stroke of the piston to prevent back flow of air from the compression chamber.

In witness whereof, have hereunto signed my name in the presence of two subscribing Witnesses.

OLOF OHLSSON. lVitnesses:

HJALMAR ZEITERSTRM, ROBERT APELGREN. 

